CO₂ Capture and Direct Air CO₂ Capture Followed by Integrated Conversion to Methane Assisted by Metal Hydroxides and a Ru/Al₂O₃ Catalyst

Abstract

Rising CO2 levels are leading to an increase in atmospheric greenhouse gas effect. Hydroxide salts have previously been shown to be promising reagents for capturing CO2. Utilizing a 5%Ru/Al2O3 catalyst, the carbonates obtained through CO2 capture can then be hydrogenated to methane. This conversion occurs at relatively mild temperatures from 200°C to 250°C under 40 to 70 bar H2 with yields of up to 100%. Natural sources of calcium carbonate, like eggshells and seashells, can also be partially converted to methane. The direct air CO2 capture and conversion of CO2 to methane was achieved as well in quantitative yields.

Integrated Carbon Dioxide Capture and Conversion to Methanol Utilizing Tertiary Amines over a Heterogenous Cu/ZnO/Al2O3 Catalyst

“…The heterogeneous Cu/ZnO/Al 2 O 3 catalyst is used industrially for methanol synthesis and in the methanol steam reforming process. Yet utilizing such heterogeneous catalysts in ICCC to produce many C1 products is still a nascent area of research. − Previously reported systems commonly employed homogeneous catalysts based on precious metals for the conversion of captured CO 2 to methanol. Notably, homogeneous Ru-pincer catalysts have demonstrated efficient conversions to methanol from capture solutions of alkali hydroxides and amines (Figure a,b). , A Ru-MACHO-BH catalyst was used for a tertiary amine-ethylene glycol-based ICCC .…”